16 research outputs found
NaI (Tl) Calorimeter Calibration and Simulation for Coulomb Sum Rule Experiment in Hall-A at Jefferson Lab
A precision measurment of inclusive electron scattering cross sections was
carried out at Jefferson Lab in the quasi-elastic region for He,
C, Fe and Pb targets. Longitudinal () and
transverse () response functions of nucleon were extracted in the
momentum transfer range 0.55 GeV/c1.0 GeV/c. To achieve the
above goal, a NaI (Tl) calorimeter was used to distinguish good electrons from
background including pions and low energy electrons rescattered from walls of
the spectrometer magnets. Due to a large set of kinematics and changes in HV
settings, a number of calibrations were performed for the NaI (Tl) detector.
Corrections for a few blocks of NaI (Tl) with bad or no signal were applied.
The resolution of NaI (Tl) detector after calibration reached at E=1 GeV. The performance of NaI (Tl) detector was
compared with a simulation
Precision measurements of A1N in the deep inelastic regime
We have performed precision measurements of the double-spin virtual-photon asymmetry A1A1 on the neutron in the deep inelastic scattering regime, using an open-geometry, large-acceptance spectrometer and a longitudinally and transversely polarized 3He target. Our data cover a wide kinematic range 0.277≤x≤0.5480.277≤x≤0.548 at an average Q2Q2 value of 3.078 (GeV/c)2, doubling the available high-precision neutron data in this x range. We have combined our results with world data on proton targets to make a leading-order extraction of the ratio of polarized-to-unpolarized parton distribution functions for up quarks and for down quarks in the same kinematic range. Our data are consistent with a previous observation of anA1n zero crossing near x=0.5x=0.5. We find no evidence of a transition to a positive slope in(Δd+Δd¯)/(d+d¯) up to x=0.548x=0.548
NEOS result and prospects
The NEOS experiment measured the inverse beta decay prompt energy spectrum
at 24 m distance from a 2.8 GWt commercial reactor core. Constraints on the active-to-sterile
neutrino oscillation parameters have been updated by the experimental result comparing
with the Daya Bay spectrum. An extended measurement which covers a full burnup cycle
will begin this Summer. By measuring the evolution of the spectrum along with the fuel compsition
change from a sole reactor core, we hope to figure out the origin of the flux and spectral anomalies
Efficacy of Acupuncture for Parkinson’s Disease over the Last Decade: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
The aim of this review is to consolidate findings from clinical investigations spanning
the past decade regarding the impact of acupuncture on Parkinson’s disease
(PD). The objective is to assess the efficacy of acupuncture as a therapeutic approach
to PD, with the intention of informing future clinical practices and advancing
the foundation for subsequent research endeavors in this area. A comprehensive
literature search was conducted to identify clinical trials exploring the effects
of acupuncture on PD between January 2014 and August 2023. Databases search
included PubMed, EMBASE, CNKI, OASIS, KISS, KMBASE, RISS, and ScienceON.
Quantitative evidence from randomized controlled trials (RCTs) was systematically
reviewed, and the methodological quality of the included studies was assessed
using Cochrane’s risk of bias tool. Meta-analysis was performed using Review Manager
(RevMan) 5.4.1 software. The systematic review encompassed a total of 38
RCTs involving 2,786 participants. Meta-analysis of 12 studies revealed that individuals
treated with a combination of acupuncture and Western medicine exhibited
notable improvements compared to those receiving Western medicine alone
or sham acupuncture alongside Western medicine. However, the overall quality of
the RCTs was deemed low, and no serious adverse events were reported. Across
clinical investigations conducted in the past decade, acupuncture appears to hold
promise as a complementary treatment for PD patients when administered alongside
Western medicine. Nevertheless, this study identifies certain limitations that
warrant consideration in future research endeavors. Enhanced emphasis on conducting
high-quality RCTs is imperative to comprehensively evaluate the efficacy
of acupuncture in managing PD
Hemodialysis as a Risk Factor for Lower Right Internal Jugular Stenosis in Cardiac Surgery Patients: A Retrospective Single-Center Study
Lower right internal jugular vein (RIJ) stenosis has been reported as a common cause of RIJ catheterization failure. However, the risk factors for lower RIJ stenosis in patients undergoing cardiac surgery is unclear. We reviewed the electronic medical records of all adult patients who had undergone cardiac operations in a single tertiary university hospital from January 2014 to January 2016. Patients were excluded if they were lack of preoperative contrast-enhanced chest computed tomography (CT) studies. Lower RIJ stenosis was defined as a ratio of cross-sectional area at the smallest level to cross-sectional area at the largest level less than 25%. Multivariable logistic regression analyses were used to investigate the risk factors for lower RIJ stenosis. A sensitivity analysis was also conducted using a cross-sectional area ratio of under 20%. The analysis included 889 patients, and the incidence of lower RIJ stenosis was 3.9%. The multivariable logistic regression analyses revealed that hemodialysis was an independent risk factor for lower RIJ stenosis (OR, 3.54; 95% CI, 1.472–8.514). Sensitivity analysis provided that hemodialysis (OR, 10.842; 95% CI, 3.589–32.75) was a significant predictor of cross-sectional area ratio <20%. Preoperative hemodialysis are significantly associated with an increased risk of lower RIJ stenosis in patients undergoing cardiac surgery. Extra care is needed during central venous catheterization in hemodialysis patients undergoing cardiac surgery
Sterile Neutrino Search at the NEOS Experiment
An experiment to search for light sterile neutrinos is conducted at a reactor with a thermal power of 2.8 GW located at the Hanbit nuclear power complex. The search is done with a detector consisting of a ton of Gd-loaded liquid scintillator in a tendon gallery approximately 24 m from the reactor core. The measured antineutrino event rate is 1976 per day with a signal to background ratio of about 22. The shape of the antineutrino energy spectrum obtained from the eight-month data-taking period is compared with a hypothesis of oscillations due to active-sterile antineutrino mixing. No strong evidence of 3 + 1 neutrino oscillation is found. An excess around the 5 MeV prompt energy range is observed as seen in existing longer-baseline experiments. The mixing parameter sin(2)2 theta(14) is limited up to less than 0.1 for Delta m(41)(2) ranging from 0.2 to 2.3 eV(2) with a 90% confidence level. © 2017 American Physical Society304
Development and mass production of a mixture of LAB- and DIN-based gadolinium-loaded liquid scintillator for the NEOS short-baseline neutrino experiment
A new experiment, called the NEutrino Oscillation at Short baseline (NEOS), is proposed on the site of Hanbit Reactors at Yonggwang, South Korea, to investigate a reactor antineutrino anomaly. The homogeneous NEOS detector having a 1000-l target volume was constructed and deployed at the tendon gallery 25 m away from the reactor core. The NEOS detector employs a linear alkylbenzene (LAB) based gadolinium loaded liquid scintillator with 10 % di-isopropylnaphthalene (DIN) based liquid scintillator to improve the particle identification via pulse shape discrimination. In this paper, we report the procedure for the mass production of the Gd-loaded scintillator for the NEOS detector. (c) Akade´miai Kiado´, Budapest, Hungary 20161111sciescopu
Comparison of fast neutron rates for the NEOS experiment
The fast neutron rates are compared at the site of the NEOS (Neutrino Experiment Oscillation Short baseline) experiment, a short-baseline neutrino experiment located in a tendon gallery of a commercial nuclear power plant using a 0.78-liter liquid scintillator detector. A pulse shape discrimination technique is used to identify neutron signals. The measurements are performed during the nuclear reactor-on and -off periods, and the fast neutron rates are found to be consistent with each other. The fast neutron rate is also measured at an overground site with a negligible overburden and is found to be ~ 100 times higher than that at the site of the NEOS experiment. © 2016, The Korean Physical Society1121sciescopuskc